1. Field of the Invention
The present invention relates to holding apparatus, position detection apparatus and exposure apparatus, moving methods, position detection methods, exposure methods, adjustment methods of detection systems, and device manufacturing methods, and more particularly to a holding apparatus which movably holds a detection system detecting a mark on an object, a position detection apparatus equipped with a detection system which detects a mark on an object and an exposure apparatus equipped with the position detection apparatus, a moving method to move a detection system which detects a mark on an object, a position detection method using the moving method, an exposure method in which a pattern is formed on an object by an irradiation of an energy beam, an adjustment method of a detection system which detects a mark on an object, and a device manufacturing method which uses the exposure apparatus or the exposure method.
2. Description of the Background Art
Conventionally, in a lithography process for manufacturing electron devices (microdevices) such as semiconductor devices (such as integrated circuits) and liquid crystal display devices, exposure apparatuses such as a projection exposure apparatus by a step-and-repeat method (a so-called stepper) and a projection exposure apparatus by a step-and-scan method (a so-called scanning stepper (which is also called a scanner) are mainly used.
Meanwhile, in a lithography process for manufacturing semiconductor devices or the like, multilayer circuit patterns are overlaid and formed on a wafer, and when the overlay accuracy between the layers is poor, the semiconductor devices or the like cannot achieve predetermined circuit characteristics, which results in detectives in some cases. Therefore, normally, a mark (alignment mark) is arranged in advance in each of a plurality of shot areas on a wafer and the position information (coordinate value) of the mark on a stage coordinate system of an exposure apparatus is detected. After that, based on position information of the mark and known position information of a pattern (e.g. a reticle pattern) that is newly formed, water alignment is performed in which the position of one shot area on the wafer is aligned with the pattern.
As a method of the wafer alignment, global alignment in which the position of each shot area is aligned, for example, by detecting alignment marks of only several shot areas (which are also called sample shot areas or alignment shot areas) on a wafer to obtain regularity of the array of the shot areas has been mainly used, in consideration of throughput. In particular, recently, the Enhanced Global Alignment (EGA) in which the array of shot areas on a wafer is precisely computed by a statistical method has been a mainstream (e.g. refer to U.S. Pat. No. 5,243,195).
However, the requirement for overlay accuracy is gradually getting stricter to cope with finer integrated circuits, and also in the EGA, in order to increase the computation accuracy, it is becoming essential to increase the number of sample shot areas, that is, to increase the number of marks to be detected.
However, since the increase in the number of sample shot areas in the EGA described above causes the decrease in throughput of the exposure apparatus, it is practically difficult to employ the measures of merely increasing the number of sample shots. Because of this, proposals are recently being made on alignment technology which uses a plurality of alignment systems (mark detection systems).